Supporting mechanism for a valve system of an internal-combustion engine

Abstract

A supporting mechanism for a valve system such as an intake or exhaust valve assembly including a spherical projection provided on a rocker arm and a support member having a downwardly concave support surface which swingably and slidably supports the spherical projection. The support surface has a recess which can hold sludge at a lower portion of the support surface. The recess is communicated with the outer surface of the support member through a hole formed in the support member.

We claim: 
     
       1. In a supporting mechanism for a valve system of an internal-combustion engine, said valve system having a support member provided on a cylinder head of said engine, a rocker arm swingably supported by said support member, an intake or exhaust valve opening or closing a port formed in said cylinder head, and means for swinging said rocker arm so that said valve opens or closes said port, said supporting mechanism comprising said support member having a downwardly concave support surface and an outer surface thereof, a spherical projection provided on said rocker arm and placed on said support surface in such a manner that said spherical surface is in slidable contact with said support surface, and means for connecting said spherical projection to said support member, characterized in that said support member has a recess for holding sludge on a lower portion thereof, said recess being communicated with said outer surface of said support member through a passage formed in said support member so that said sludge is discharged outside of said support member. 
     
     
       2. A supporting mechanism according to claim 1, wherein said support surface is formed on a cylindrical portion protruding from the upper surface of said support member, an annular groove being formed in a lower peripheral portion of said cylindrical portion, a hole being opened between said annular groove and said recess, said hole extending in a substantially horizontal direction and connecting said recess to said annular groove. 
     
     
       3. A supporting mechanism according to claim 1, wherein only one said passage is opened between said recess and the outside of said support member. 
     
     
       4. A supporting mechanism according to claim 1, wherein a plurality of said passages is opened between said recess and the outside of said support member. 
     
     
       5. A supporting mechanism according to claim 1, wherein said support member is a pivot mounted on a cylinder head of said internal-combustion engine. 
     
     
       6. A supporting mechanism according to claim 1, wherein said spherical projection is formed on an adjusting screw threading mounted on a base portion of said rocker arm.